Adds documentation for all of the date time functions using the new
cli-like format extracted from the csv spec. In the process of doing
this I noticed that the `WEEK` function isn't exposed as a function.
This exposes it for consistency.
Relates to elastic/x-pack-elasticsearch#2898
Original commit: elastic/x-pack-elasticsearch@0459b24cb9
I went to write some docs for datetime functions that look like:
```
SELECT YEAR(CAST('2018-01-19T10:23:27Z' AS TIMESTAMP)) as year;
year
2018
```
because I figured they'd be pretty easy to read because they didn't
require any knowledge of a data set. But it turns out that constant
folding doesn't work properly for date time functions because they don't
actually apply the extraction.
Original commit: elastic/x-pack-elasticsearch@aa9c66b2c7
Since we don't do any serialization of Cursor classes from the Transport
side (it is treated entirely as a string), we don't actually need to tell anyone
about SQL's writeables
Original commit: elastic/x-pack-elasticsearch@ad2c10e327
This is the next step in removing the top level sql directory.
I named the directory `sql-cli` instead of `cli` because that puts it at
the maven coordinates `org.elasticsearch.plugin:sql-cli` instead of
`org.elasticsearch.plugin:cli`.
Relates to elastic/x-pack-elasticsearch#3363
Original commit: elastic/x-pack-elasticsearch@d41a57a136
This moves SQL's server project into `plugin:sql` without modifying how the integration is performed. I know that it is not correct with regards to the x-pack modularization but I think it is a good first step.
Original commit: elastic/x-pack-elasticsearch@2f40d02e4d
